为研究典型单转向轮系统摆振机理及稳定性,建立杠杆驱动轮椅车转向轮系统非线性动力学微分方程,应用ODE方法进行求解；搭建了参数可调的转向轮摆振实验装置,利用实验手段研究摆振现象,验证了转向轮系统动力学模型的有效性；并对此动力学模型线性化,进行稳定性分析；利用遗传优化算法对转向轮系统进行参数优化设计,针对实验研究的转向轮摆振实验装置进行稳定性分析,采用增加阻尼轴承的方法改善实验中转向轮系统的稳定性.通过研究转向轮系统参数变化对摆振的影响规律,提出防范摆振的方法,获得具有实用价值的结论:通过增加转向轮拖距长度、合理选择质量参数或者增加系统的阻尼都可以减小甚至消除摆振.因此,该研究具有较好的工程实用价值,并对类似转向轮系统稳定性分析有一定的参考价值.%In order to investigate the mechanism and stability of caster wheel shimmy,2DoFs dynamic model of lever propulsion wheelchair steering wheel was established by analytical mechanics. This dynamic model was derived from Lagrange equation and its numerical solutions were solved by Ordinary Differential Equation (ODE) method. A new physical steering wheel model with adjustable parameters was built to verify the mathematical model. In the experimental stage, the theoretical results obtained from mathematical model as well as the dynamic behavior of towed wheel within different cases were successfully verified by vibration measurements. Stability analysis was conducted by Routh criterion on a linear dynamic model. To avoid the shimmy in the design stage,the genetic algorithm was applied to optimization design of the steering wheel system. Shimmy can be avoided after replacing a damped bearing with a set of reasonable parameters. Based on the stability analysis and optimization design conclusions,the shimmy problem of physical steering wheel has been solved. To avoid and eliminate shimmy,some practical suggestions are offered due to the effects of system parameters on shimmy, for instance, increasing length of the trail, applying a damped bearing and adopting reasonable parameters of geometry and mass. Therefore,the presented method is of good practical engineering value, and it also has a certain useful value for similar steering wheel system stability analysis.
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